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Electrospun Fibrous Membrane with Confined Chain Configuration: Dynamic Relaxation and Glass Transition.
Zhang, Nuozi; Wang, Chenhong; Chen, Hao; Wu, Jiaen; Han, Charles C; Xu, Shanshan.
Afiliação
  • Zhang N; Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China.
  • Wang C; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
  • Chen H; Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China.
  • Wu J; State Key Laboratory of Polymer Physics and Chemistry, Joint Laboratory of Polymer Science and Materials, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
  • Han CC; Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China.
  • Xu S; Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China.
Polymers (Basel) ; 14(5)2022 Feb 26.
Article em En | MEDLINE | ID: mdl-35267762
Thermodynamic glass transition processes of electrospun membranes were first introduced to study their dynamic relaxation nature, which is not constantly in equilibrium. The relaxation modes of electrospun membranes are slow but measurable near and above the Tg, given the stretched chain over long distances. Based on differential scanning calorimetry (DSC) experiments and the general principle of mode-coupling theory (MCT), endothermic peak temperature and relaxation enthalpy were used to analyze the relaxation process by capturing these instantaneous "arrested" structures. The short- and long-wavelength relaxation modes could be identified with different annealing times and temperatures relative to DSC-measured Tg for electrospun membranes with different molecular weights. Results clearly showed the dynamic nature of a glass transition in polymeric materials. Tp and enthalpy loss initially increased and then directly decreased with the increase in annealing time. When Ta > Tg, regardless of the size of the molecular weight, the Tp and enthalpy loss of the PLGA fibers would directly decrease, and the curves would shift toward the melted one. Combination of electrospinningand normal DSC instrument can be used to investigating the dynamic relax process through an adequately designed kinetic scanning procedure. This result can be explained by the general principle of MCT-type dynamic theory.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Revista: Polymers (Basel) Ano de publicação: 2022 Tipo de documento: Article País de afiliação: China

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Revista: Polymers (Basel) Ano de publicação: 2022 Tipo de documento: Article País de afiliação: China